Flexible, or floppy disk, drives are well known in the data processing industry, and are presently widely utilized as a primary peripheral input/output device for personal computers. In this application, the drives typically use a flexible five and one-fourth inch disk contained within a flexible cartridge, or envelope.
To lower the cost of flexible disk drives, it is desirable that the drives be assembled on an automated manufacturing line having robotic arms. To accomplish this, the disk drive must be designed for ease of assembly, but nevertheless must have precise registration between key elements of the assembled drive to ensure that recorded disks may be interchanged between drives.
Modularization of some assemblies in flexible disk drives is known. An example is the disk drive described in U.S. Pat. No. 4,139,877 issued to R. H. Townsend. While the modularization techniques as shown in this patent make it easier to assemble or interchange subassemblies in flexible disk drives, the drive is still relatively complex and is felt not to lend itself to robotic assembly.
Splitting the elements of a disk drive into critical and not critical groupings is taught in an article entitled "Magnetic Disk Drive Machine" by J. J. Holecek et al (IBM Technical Disclosure Bulletin, Volume 22, Number 10, March, 1980, pages 4657-4660). All of the elements of the disk drive that require precise position registration are placed on one frame, and a second frame, carrying the elements of the disk drive that have a larger position tolerance, is bolted to the first frame. While the technique taught in the Holecek et al publication could be used to assist automated assembly, it is not usually possible to place all critical elements of the drive on one frame and/or constitutes a design constraint.